Question

我的第一个C ++程序有问题。我写了这个计算器，但由于某些原因，当我输入操作字符时它退出。它没有显示任何错误或什么，它只是退出。这是Visual C ++的代码

#include <iostream>

using namespace std;

int  main()
{
    float n1;
    float n2;
    float n3;
    int op;
    cout << "Welcome to my calculator" << endl;
    cout << "Type the first number: ";
    cin >> n1;
    cout << "Type the second number: ";
    cin >> n2;
    cout << "Type the number for the operation" << endl;
    cout << "1 = addition" << endl;
    cout << "2 = subvision" << endl;
    cout << "3 = multiply" << endl;
    cout << "4 = division" << endl;
    cin >> op;
    if(op == 1)
    {
        n3 = n1 + n2;
        cout << "The result is " << n3 << endl;
    }
    if(op == 2)
    {
        n3 = n1 - n2;
        cout << "The result is " << n3 << endl;
    }
    if(op == 3)
    {
        n3 = n1 * n2;
        cout << "The result is " << n3 << endl;
    }
    if(op == 4)
    {
        n3 = n1 / n2;
        cout << "The result is " << n3 << endl;
    }
    return 0;
}

Answer 1

您可能希望查看switch语句而不是多个if。然后，当您的预期案例都不匹配时，您的默认语句可以捕获正在发生的事情。

switch (op)
{
case 1:
{
   // add
   break;
}
// other cases
default
{
   // something unexpected, print an error
}
}

Answer 2

您可以修复插入

的插件

system("pause");

在返回之前的末尾（如果你在windows下编码）

C ++计算器退出

2 个答案: